She quoted one message from Fersen as saying, "I live and exist only to love you — adoring you is my only consolation. My God, how cruel it is to be so near and not be able to see each other!"

And based on her research, Farr says she has "compelling evidence" that Marie Antoinette's son, Louis Charles, and daughter, Sophie, were fathered by Fersen.

Marie Antoinette wed King Louis XVI when she was just 14 years old as part of an arranged marriage. And Farr says she began her relationship with Fersen four years later.

Unfortunately, if you want to learn more about this alleged affair, you'll have to wait a little while longer. Farr's book will be released in the U.K. in March and the U.S. this summer. But you could just watch the movie to hold you over until then. (Video via Columbia Pictures / "Marie Antoinette")